We talked here about which Bluetooth features we plan to include when we ship and what we hope to add over time. But to quote myself 
:
We generally try to be thoughtful about which features we add to our Device OS because more features means more flash and RAM used by the system and less resources available to your application. Since the primary role of Bluetooth in Particle Mesh is for device setup and diagnostics, we don’t plan to support generalized and broad Bluetooth functionality when we ship...In the fullness of time, we’d like to add API support for Bluetooth. However, we will be focusing our efforts for the initial release on the primary use case of device setup and diagnostics over Bluetooth. We have other ideas on how we can leverage Bluetooth that will also not be included at launch.
What use case do you have in mind that would use the BLE Peripheral role?